Mechanical sorter for uranium ore



Aug- 15, 1961 D. E. LouGHRAN 2,996,186

MECHANICAL SORTER FOR URANIUMORE Filed Nov. l, 1957 2 Sheets-Sheet l DAVID E. LOUGHRAN y ATTO R N EY Aug. 15, 1961 D. E. LOUGHRAN 2,996,186

MECHANICAL soRTER FOR URANIUM ,ORE

Filed Nov. 1, 1957 2 sheets-smet 2 INVENTOR. DAVID E. I OUGHRAN I l a ATTORNEY 2,996,186 MECHANICAL SORTER FOR ORE David E. Loughran, 4044 SE. Woodward, Portland, Oreg. Filed Nov. 1, 1957, Ser. No. `693,897 2 Claims. (Cl. 209-41115) This invention relates to sorting means whereby pieces of `ore which contain uranium can be separated out from other pieces of the same ore which contain no uranium or in which the uranium content is in such insignificant amounts as to be negligible and thus not sulilcient to justify further processing.

Heretofore the checking of ore for uranium content has been confined mainly to a manual operation in which the ore is spread out on a platform and each piece tested individually by bringing a Geiger counter, or similar indicator which is ksensitive to radioactive elements, into close proximity to each piece individually. Those pieces of ore in which such checking indicates no appreciable amount of uranium (or other radioactive elements), and which consequently are of no value, are deposited into a waste pile and the remaining pieces are collected for subsequent processing in a uranium mill. Obviously such manual sorting is time-consuming, expensive, and frequently inefficient.

An object of the present invention is to provide suitable mechanically-operated -means for sorting out pieces of uranium-containing `ore to take the place of the manual procedure above mentioned and which will enable the `sorting to be done more efficient-ly.

Since the preliminary sorting out of uranium-containing ore frequently must take place at small, remotely situated uranium mmm, where skilled labor or technicallytrained personnel are Vnot likely to be available, another object of the invention is to provide an ore-sorting device which will be sutiiciently simple for operating so that the desired sorting can be accomplished by semiskilled miners or even by entirely unskilled personnel.

A iiurther object of the invention is to provide a mechanically-operated oresorting device which will be relatively light in weight so that it can easily and profitably be transported to remote locations when desired, and which will be sufficiently rugged in construction to stand up under the hard and `abusive service which, under some circumstances, is to be expected.

A still further object is to provide a simple and practical sorting device, arranged specifically for use with uranium-containing ore, which will be relatively inexpensive to manufacture so that it can be placed on the market at a moderate price and be available to individual prospectors and miners for uranium who may have very limited capital on which to operate.

The way in which these objects and incidental advantages are attained and the construction and manner of operation of the ore sorter in which the present invention is embodied will be easily understood from the following description.

In the following description reference is made to the accompanying drawings, wherein:

FIGURE l is a side elevation of the device;

FIGURE 2 is a front elevation of the same, thus taken from the left of FIGURE l, drawn to a larger scale, with portions broken away for clarity; and

FIGURE 3 is a fragmentary section taken on line 3-3 of FIGURE 2.

As shown in FIGURES l and 2, the device includes a frame, indicated in general by the reference 10, preferably shaped substantially as illustrated, the frame members being preferably of angle iron or other suitably rigid material joined together by welding or bolting so as to constitute a rigid and sturdy frame structure capable of supporting the various parts of the machine without being unnecessarily heavy or expensive to fabricate.

An endless conveyor belt 11, preferably comprising a suitable link chain, passes around a driven pulley or sprocket 13 (FIGURE l) at the bottom of its course and around a corresponding pulley or sprocket 15 at the top of its course. The driven sprocket 13 is secured on a shaft 14, mounted in suitable support bearings in the frame structure, and the upper sprocket 15 is mounted on the shaft 16.

A series of spaced buckets or cups 12 are secured on the endless belt or chain 11, the buckets all being identical in shape and size and spaced equal distances apart. The buckets `are of such size that they will pick up and carry approximately equal amounts of the ore which is being tested and sorted, the purpose of these travelling buckets being to raise the ore and drop the ore into the top of a chute 28, as later explained.

A motor M which in most situations would be an internal combustion motor, but which might also be an electric motor, is mounted in the bottom of the frame 10 and drives an endless belt 17 which passes around the pulleys 18 and 19. The lower pulley 18 is secured on a shaft 20. A sprocket 21, also secured on the shaft 20, drives a sprocket chain 22 which in turn drives a sprocket wheel 23 secured on a shaft 24. A second drive sprocket 25, secured on the shaft 24, drives a sprocket chain 26 which passes around a sprocket wheel 27 secured on the shaft 14 (FIGURE 1). Thus the operation of the motor M causes the conveyor belt 11, with the ore-carrying buckets 12 to be driven in the direction indicated by the arrows in FIGURE l.

A uranium-sensitive indicator, such as the well known Geiger counter, or a scintillation counter, is mounted in a housing 42. The open bottom end of the housing 42 faces the conveyor belt 11'and is spaced a short distance therefrom in the relative position shown -in FIGURE l. The housing 42 is mounted on a hinged support 45 which is hinged on the -main frame 10 of the machine. The hinged support 45 rests against an adjustable stop 47, being held against the stop by gravity and by the coil spring 46. A shield 48, `fnmly secured on the hinged support 45, extends, between the bottom end of the housing 42 and the conveyor belt 11, being spaced fromfthe adjacent end of the housing 42 as shown. The shield 48 prevents any oversize rock or piece of ore, which might inadvertently be carried by one of the buckets 12 on the conveyor 11, from striking the housing 42, and thus contact between such oversize piece of ore and the shield 48 would merely result in the hinged support 45 temporarily being pushed outwardly against the force of the spring 46. Preferably the material from which the shield 48 and also the housing 42 are made contains a substantial amount of lead so as to protect the counter in the event not only large pieces of ore but also pieces with very high uranium content should inadvertently be brought into close proximity with the counter when the counter has been arranged for testing ore with only a relatively low uranium content.

The ore to be sorted is fed or shoveled into a boot or bin 51 Ithrough which the conveyor 1.1 passes at the bottom of its course. Preferably the ore which is to be tested and sorted by the device should previously be screened or sized so that the pieces or ore will be kept consistently within a limited size range. Since the buckets 12 are all the same size they will pick up approximately equal amounts of ore. When a bucketpasses beneath the counter in lthe housing 42, carrying ore in which there is an appreciable amount'of uranium, this will cause momentary activation of the counter, and this activation in turn is utilized as a form ofvelectrc energy in the manner and for the purpose presently explained.

The chute into which the buckets 12 discharge their pieces of ore, divides a short distance below its top intake into two branch chutes 29 and 3G (see also FIG- URE 3), Which branch chutes are similarly arranged and positioned but which have their bottom discharging ends sufficiently spaced apart from each other so that the discharge from each branch chute can be separately collected.

A hinged shutter or gate 31 is mounted at the lower central point in the chute 28 where the chute 28 divides into the two branch chutes 29 and 30, as shown in FIG- URE 3. The gate 31 is secured on a pivot shaft 32 (FIGURE 2) which extends through the chute and is rotatably mounted in bearings in the opposite walls of the chute. As apparent from FIGURES 2 and 3, the gate 31 is of the proper size to enable it to close off either of the branch chutes `29 or 30.

An arm 33, secured to an outside end of the gate shaft 32 is pivotally connected to the end of a piston rod 34 of the piston located in an air cylinder 35. The arrangement is such that whenever a charge of compressed air is delivered into the air cylinder 35 the downward movement of the piston rod will cause the gate 31 to swing over to such position as to close off the branch chute and open the branch chute 29; and when the charge of air into the cylinder is shut off and the air pressure in the cylinder has had a moment in which to be released, the gate 31 will be returned to its normal position, shown in FIGURES l and 3 (thus closing the branch chute 29 and leaving the branch chute 30 open), by the upward return movement of the piston rod 34 and the action of the spring 50, The purpose of the arrangement, as will be apparent, is to have the pieces of uranium-containing ore pass down the branch chute 29 and have the rest of the material pass down the branch chute 30 so that the latter material can be wasted.

Air under pressure from a compressor 36 is delivered through a tube 37. An air control valve, located in `a housing 3S, allows the air from the tube 37 to pass into the cylinder 35 through a tlexible tube 4) when the valve is opened and allows air in the cylinder to be exhausted through a tube 39. The air control valve is operated by a solenoid also located in the housing 38, and, since such solenoid-operated control valves are old in the art and well known, no description of this air control is necessary.

A conductor 43 leads from the counter in the housing 42 to an amplifying assembly located in a housing 41. The amplifying assembly is arranged so as to actuate a microswitch (not shown) also located in the housing 41. The microswitch is connected in the circuit to the solenoid previously mentioned, which solenoid is located in the housing 3S and is connected with the conductor 44. The amplifying assembly and solenoid circuit are supplied with power from an outside source (thus either from a power line or from a suitable battery) by the conductor cable 49.

The air compressor 36 is driven from the motor M by means of the belt 17 and pulley 19. Other sources of air or gas under pressure could of course be substituted for the motor-driven compressor 36. Thus, with the operation of the device, ore is carried by the buckets 12 past the sensitive counter `in the housing 42, the counter being a predetermined slight distance from the pieces of ore as the pieces of ore pass the counter. When a piece of ore containing uranium (or other radioactive element) moves past the sensitive counter it causes activation of the counter. This activation of the counter operates through the intermediary of the amplifying assembly and solenoid-operated air control valve previously mentioned to cause the piston in the air cylinder 35 to be thrust downwardly and thus to swing the gate 31 from the full line position in FIGURE 3 over to the position indicated by the broken lines. This opens the branch chute 29 and closes ot the branch chute 30. Consequently when ore which produces such activation of the counter reaches the point Where it is discharged from the conveyor, it drops down through branch chute 30. A moment later the gate 31 is returned to its normal position, closing branch chute 30. Should the ore being carried in the lnext successive bucket 12 contain no appreciable titanium (or other radioactive element) and thus cause no activation of the counter, the gate 31 will remain in this normal position with the result that this next ore will pass down the branch chute 29 and be automatically delivered into the Waste pile.

The pieces of ore which are being tested and sorted during a running of the device should be from the same general area so that the amounts of uranium (or other radioactive elements) which may be contained in the ore pieces will be within a reasonably close range and within the range for which the counter is suited for operating most effectively and reliably. The counter must of course be sutliciently sensitive so that it will clear quickly after the passage of each piece of activating ore, so that the counter will be in condition to be activated again by the ore in the next successive bucket, and the spacing of the buckets on the conveyor 11 as well as the speed of travel of the conveyor 11 must be properly arranged so that effective and eicient operation of the counter, and thus most eflicient operation of the device, can be obtained.

Various minor modications in the construction of the device will of course be possible without departing from the principle of the invention.

I claim:

l. In a device of the character described for sorting out uranium-containing ore, a supporting frame, an endless conveyor movably mounted on said frame and leading from the lower portion to the upper portion of said frame, a main chute leading downwardly from the upper termination of said conveyor for receiving the pieces of ore discharged from said conveyor, a uraniumsensitive counter positioned above said conveyor near the discharging end of said conveyor in the upper portion of said supporting frame and so arranged that said counter will be activated when a piece of uranium-containing ore moves past said counter on said conveyor, a housing for said counter, support means for said housing hinged on said frame enabling said housing to be moved towards or away from said conveyor, an adjustable stop limiting the movement of said support means towards said conveyor, a spring normally holding said support means against said stop, a counter-protecting shield carried by said support means and extending between said counter and said conveyor, a pair of separate branch chutes leading from said main chute, a gate in said main chute, said gate normally causing pieces of ore deposited in said main chute to be discharged through one of said branch chutes, control means for temporarily moving said gate to cause ore in said main chute to be discharged through the other of said branch chutes, an amplifying assembly connected to said counter, and operating means for said control means connected with said amplifying assembly, whereby, when a piece of uraniumcontaining ore on said conveyor lis brought close to said counter, the activation of said counter will result in said `gate being moved to cause said piece of ore to be discharged through said other of said branch chutes of said main chute.

2. A mechanical sorter for uranium ore, said sorter comprising a supporting frame, an endless ore-carrying conveyor movably mounted on said frame and leading from the lower portion to the upper portion of said frame, a main chute leading downwardly from the upper termination of said conveyor and receiving the ore discharged from said conveyor, a pair of branch chutes connected to said main chute, a gate in said main chute at the entrance to said branch chutes, said gate normally maintaining one of the said branch chutes closed, gate 5 control means for movin-g said gate momentarily to open sa-id last mentioned branch chute and close the other branch chute, a uranium-sensitive counter positioned above said conveyor and in close proximity to the upper termination of said conveyor, a housing for said counter, support means for said housing hingedly mounted on said frame and enabling said housing to be moved towards or away from said conveyor, spring means exerting a force to move said housing towards said conveyor, a stop limiting the movement of said housing toward said conveyor, a counter-protecting shield spaced below said housing and connected with said housing, an air cylinder and piston in said gate control means, a motor operating said conveyor, an air compressor operated by said motor and connected with said cylinder, a solenoid-operated valve controlling the delivery of air to said cylinder, an amplifying assembly connected -to said counter, and

means including said amplifying assembly for actuating the solenoid for said valve whenever said counter is activated by the passage of uranium-containing ore beneath said counter.

References Cited in the le of this patent UNITED STATES PATENTS 

